The image quality is not good, sadly - it's a learning curve I guess! Does the original footage look this poor? You may have rendered the proxy files by mistake or just used the wrong compression on export. And the right eye is really blurry, left eye less so. If the original footage looks like this then unless the camera was absolute garbage your mistake was not providing enough light for the little sensor to discern detail.
As for scale, it's a little on the small side for me (no biggy, except when the image quality is this low you can't zoom in on those half dozen pixels - your new 8k cam will give the user more freedom to tweak the image to their tastes). You are right that Era Queen looked too big, but scale can be reduced in post to an extent. Scale cannot be increased so easily because instead of compacting pixels you have to enlarge them, never a good thing. And your camera is a little too far away for me personally, just a teeny bit.
Where to place the camera will take some experimentation and will change depending on the rig. Remember, this is a camera not the human eye so you can't just put the camera where your head is and expect perfect real life experience. Every camera / lens combo has a different perspective, and you'll find your new Canon makes things look too big. Camera placement is always a compromise and you have to be flexible with the ultimate goal being the best experience for the viewer. You're worrying about the height of the viewer, as if that makes much difference - it really doesn't in most cases because you are dealing with torso length of viewer (eyes to cock) not full height. This link shows you the difference in average torso lengths for people of varying heights: https://hikemuch.com/average-torso-length/ - you may be surprised by how similar a short and tall viewer are in this respect. If the scene looks perfect to you in VR, you're fine.
One thing to note - passthrough is good but it's not perfect, and for me I perceive scaling and distance differently in passthrough and VR. Basically, Quest 3 passthrough is very slightly too "close" versus real life. It's a subtle difference but a scene can look fine in VR then not with passthrough enabled, and vice versa. If your focus is passthrough then I would aim for perfection in that, according to current (quest 3) standards.
Hands - ideally you should not use your hands at all in passthrough. In regular VR porn it's up for debate, some people are ok with it, some not. In passthrough it's not ok, especially if you're going to key out your hands! If you must touch the model for your own reasons, the hands have to be shown, as flesh colored human hands. Edit - I see you've addressed this and will not use hands in future - awesome 🙂 Hopefully this means you also won't jerk yourself off to finish, which is my least favorite thing. Let the girl finish you off, even if you have to cut, pause the shoot to get yourself ready then cut to her finishing. Dudes wanking on screen is not what straight porn is about IMHO.
Camera handling. Either be more careful with handling the camera / rig / mics (like do not fucking touch them at all once you're rolling) or fix all that terrible handling noise in post. Audio is a big deal, and the loud banging every time the camera is knocked (and this is just a BJ scene!) is not pleasant.
Finally, you state above that the camera cannot be tilted at all. Yes, it can. You just have to keep the horizon level, but you can tilt up or down to best suit the scene. The camera is a proxy for the viewer's head and the angle of view should approximate a comfortable angle for the viewer.
Good luck!
